1. Field of the Invention
The invention relates to a technique for setting three oil paths with the use of two switching valves.
2. Description of Related Art
There is well known a hydraulic control circuit that alternatively switches by a switching valve between an oil path that supplies hydraulic oil to a hydraulic actuator and an oil path that drains hydraulic oil from the hydraulic actuator. For example, a hydraulic control device for an automatic transmission, described in Japanese Patent Application Publication No. 6-174079 (JP 6-174079 A) is such a hydraulic control circuit. JP 6-174079 A describes the hydraulic control device including two oil paths that communicate with a clutch via a switching valve that is actuated by a solenoid valve. When supply of hydraulic pressure via one of the oil paths fails, the hydraulic control device switches the oil path communicating with the clutch to the other one of the oil paths by the switching valve.